1. Field of the Invention
The present invention relates to nanocrater catalyst in metal nanoparticles and their preparation methods, more particularly, to a nanocrater catalyst in metal nanoparticles with a nanocrater form of hole structure at the center of the catalyst, a preparation method thereof including a plasma etching and chemical etching process (“PTCE process”) and nano-sized materials and/or articles manufactured by using the nanocrater catalyst in metal nanoparticles.
2. Description of the Related Art
Nano-sized metal particles have electric, optic and/or magnetic properties different from those of bulk metal materials and have recently received increased attention in a wide range of applications.
Metal nanoparticles having nano-sized holes are possibly combined with advanced sciences and technologies to be used in a variety of applications. Extensive research and investigation into metal nanoparticles is proceeding all over the world, since the metal nanoparticles are absolutely required as a catalyst in production of nano-sized materials and/or articles.
Accordingly, metal nanoparticles used in production of nano-sized materials closely correlate with structure and characteristics of the resulting nano-sized materials and/or articles. In order to produce a desired product with desired structure and characteristics, there is a requirement to study structure and characteristics of a catalyst, that is, metal nanoparticles used as the catalyst.
However, there are still serious problems or difficulties in preparation of metal nanoparticles with desired structure and characteristics and, in the present circumstances, studies and developments of the metal nanoparticles have not considerably progressed.
Commonly known methods or technologies in the related arts, for example, electron beam lithography, micro-contact printing, shadow mask and the like have been employed to control alignment or orientation of particles and/or particle size. However, such methods have drawbacks in that these are not commercially available due to high production costs, and substrates to be processed are restricted to very small dimensions.
Another method was proposed to provide metal catalysts with uniform dimension using AAO (anodic aluminum oxide) templates. But, commercially available AAO templates usually have a hole size of more than 100 nm and are substantially unable to have a hole size of less than 50 nm regardless of variation of the processing conditions.
Consequently, there is still a strong demand to develop novel metal catalysts with controlled structure sufficient to produce nano-sized materials and/or articles having desired structure and characteristics.